The Biological Importance of Water
The Biological Importance of Water Water is essential to life itself, with out water life on earth would not exist. Water is a major component of cells, typically forming between 70 and 95% of the mass of the cell. This means that we are made from approximately 80% water by mass. Water also provides an environment for organisms to live in as 75% of the earth is covered in water. Water itself is a simple molecule made up of 2 hydrogen atoms and one oxygen atom - H20. The hydrogen and oxygen atoms are bonded covalently. Covalent bonds are formed by sharing electrons in the outer orbits of the quantum shells. In the case of water however the large number of protons in the oxygen nucleus have a stronger attraction for these shared electrons than the comparatively tiny hydrogen nuclei. This pulls the electrons slightly closer to the oxygen nucleus and away from the hydrogen so that the oxygen develops a slight negative charge and the hydrogen's a slight positive charge. This makes the molecules slightly polar. This slight charge means that when water molecules are close together the positively charged hydrogen atoms are attracted to the negatively charged oxygen atoms of another water molecule to form a weak hydrogen bond. The bonds are weak individually but the great number of them means that the total force keeping the molecules together is considerable. Water is an unusual
The biological importance of water
The Biological Importance of Water Water is argued to be the most important molecule. It is essential to life itself and without it life on earth would not exist. It is a major component of cells making up between 70% and 95% of the mass of a cell. Humans are made from approximately 70% water whereas soft-bodied creatures such as jellyfish are made up by 96% water by mass. As well as forming organisms it also provides an environment for them to live in as 75% of the earth is covered by water. Water is one of the simplest linear molecules made up of two hydrogen atoms and one oxygen atom. Its chemical formula is H2O and the atoms are joined by covalent bonds. These are formed when electrons in the outer shell are shared, however in water's case there are a large number of protons in the oxygen nucleus, which have a strong attraction to the shared electrons. This attraction is stronger than the one from the tiny hydrogen nuclei. Therefore the electrons are pulled slightly closer to the oxygen nucleus, developing a slight negative charge, and away from the hydrogen, causing a slight positive charge. This makes the molecules slightly polar. This charge means that the negatively charged parts of one molecules will be attracted to the positively parts of another to form a weak hydrogen bond between the water molecules. Individually these bonds a very weak but the sheer number of
The Biological Importance of Water as a solvent and as a medium for living Organisms.
The Biological Importance of Water as a solvent and as a medium for living Organisms Structure Water is made up of 2 basic components, these being Oxygen and Hydrogen. Water has the molecular formula H2O. We are about two-thirds water and require water to live. Life now, could not have evolved without liquid water and would die without it. For example, droughts cause famines and floods cause death and disease still to this day. Because of its importance, water is the most studied material on Earth. Water in human biology Water is very important as part of the diet of all humans and other living organisms. For humans, 60% of the water we take in comes from drinks, 30% comes from food and the remaining 10% is metabolic water, a product of respiration. Most substances found in the body, dissolve in water except fats and other large polymers such as fibrous proteins. Water is the medium in which substances are transported around the body. This shows how two thirds of the body is made up of water. It is the most important, yet basic substance ever known. Cohesion This is due to the hydrogen bonds that hold water molecules together. It is very important especially to plants which use the cohesiveness to take water in through the xylem. The cohesiveness gives the water the "stickiness" or surface tension and basically holds the droplet or droplets, together. This is due to
The Biological Significance Of Water.
The Biological Significance Of Water. In this essay I will explain just how important this seemingly simple substance is to life on Earth. This will include references to it's chemical structure and it's physical properties. Water is the common name given to the liquid state of the hydrogen-oxygen compound H2O. Water is a very important substance as it makes up 70% of an individual human cell making by mass most plants and animals (including humans) between 65 and 95 per cent water. Up until the 18th century ancient philosophers thought that water was just a basic element. However in 1781, it was discovered, by the British chemist Henry Cavendish, that water could be synthesized using a mixture of hydrogen and air. This led a French chemist Antoine Laurent Lavoisier, two years later to suggest that water was in fact a compound of oxygen and hydrogen and not an element as originally thought. With today's technology many complex tests have been carried out on water and a lot is now know about this substance, which supports all living things on this planet. Water is the only substance that occurs at all three states of matter, solid, liquid and a gas at ordinary temperatures. It occurs as a gas as water vapour and is fog, steam and clouds. Water occurs as a liquid over three quarters of the Earths surface as oceans, rivers, lakes and swamps. Ice the solid form of water is
The Biological Significance of Water.
The Biological Significance of Water Water, H2O is the basis of all life on earth. Without it, there would be no life at all. That fact alone makes this substance biologically important. Why it is that this substance is so important, will now be explained. The water molecule consists of two Hydrogen atoms and one Oxygen atom, and these bond together by covalent bonding. However, both the oxygen and the hydrogen atoms are left with a slight charge. Oxygen has a slight negative charge, and hydrogen has a slight positive charge. When balanced out over the molecule, there is no net charge. However, in liquid water, the hydrogen from one molecule is electrically attracted to the oxygen in another. This makes water a dipolar molecule, and an oxygen atom from one molecule and a hydrogen atom from another molecule form a weak hydrogen bond. This hydrogen bond although weak when compared to covalent bonds, is strong enough so that water molecules have to have a lot of energy transferred to them before they can break the hydrogen bonds, giving water a high specific heat capacity. The hydrogen bonds mean that water is liquid at room temperature, unlike many similar compounds. Hydrogen sulphide (H2S) is a gas, which means that oxygen, being a lighter element then sulphur should be in gaseous form at room temperature when bonded with hydrogen as water. However, this means little in
The affect of light intensity on photosynthesis.
Deniz Guner The affect of light intensity on photosynthesis AIM My aim in this investigation is to try and find out what affect light intensity has on photosynthesis. BACKGROUND INFORMATION Photosynthesis is that plants carry out to make food .Carbon dioxide(CO2) and water(H2O) are the reactants and glucose(C6H12O6) and oxygen(O2) are the products of this reaction . In order for this reaction to occur the energy of sunlight is required . Photosynthesis happens by carbon dioxide getting into the leaf through small holes on the under surface of the leaf called stomata and the water is aquired through the soil by the roots.the reaction involving carbon dioxide and water takes place in chloroplasts.these chloroplasts contain a green chemical called chlorophyll , this is what gives plants their green colouring. The main stages of photosynthesis are the chlorophyll absorbs sunlight energy and uses this to split water into hydrogen and oxygen.this hydrogen is then combined with carbon dioxide to form sugar glucose.the oxygen from the splitting of water escapes as a waste product. the limiting factors in this reaction are:- the amount of carbon dioxide, as this affects the amount of glucose produced. the light intensity ,as this provides the energy required to split water into hydrogen and oxygen. And the temperature, as photosynthesis is controlled by enzymes which
Rate of photosynthesis.
Rate of photosynthesis Results Distance (cm) Bubbles per minute Average Light intensity 2 3 0 240 249 251 246.7 5 201 222 214 212.3 1000 0 83 85 88 85.3 5800 5 54 52 58 54.7 3570 20 28 18 24 23.3 2320 25 93 88 90 90.3 780 30 67 65 70 67.3 320 35 53 50 4.8 50.3 050 40 38 38 37 37.7 850 45 26 25 24 25 690 50 7 7 8 7.3 580 The temperature of the water stayed a constant of 20 degrees throughout the experiment. Analysis The graphs that I have drawn from my results confirm my prediction that as light intensity increases, so does the rate of photosynthesis. All of my results fall into this pattern. This is because the energy of the light is used to drive the reaction and obviously the closer the light is, the more energy given to the plant. Also the light would reach a larger surface area of the plant as it is more focused. I can also see from my results that after a certain light intensity, the graph begins to curve and level off, which shows that the plant can only absorb so much light energy and then any increase after this point does not affect the reaction. Therefore light stops being a limiting factor to the rate of photosynthesis. This is because for water and carbon dioxide to react and for photosynthesis to occur, chlorophyll is needed. The light travels through the transparent epidermal cells to a
Rate of Photosynthesis
Rate of Photosynthesis Introduction I am going to perform an experiment to test the rate of photosynthesis for different light intensities. Photosynthesis is performed by plants only. It is the process they use to create glucose, the food that all living things consume, from sunlight. It occurs in the green cells of plants in the palisade layer of the leaf. The chemical equation for photosynthesis is sunlight 6CO2+6H2O C6H12O6+6O2 chlorophyll CO2 is carbon dioxide, which the plant will take from the air via the leaves. H2O is water, which the plant takes up through the roots. C6H12O6 is glucose, the food the plant will burn when it respires. O2 is oxygen, and although this is used during respiration enough of it is produced for there to be surplus amount, which secondary consumers (i.e. herbivores) can then use to respire (whilst they eat the plants). All living things perform respiration and it takes place in every cell of the organism. The chemical equation for respiration is C6H12O6+6O2 6CO2+6H2O+Energy The rate of respiration for a plant rarely changes, whereas the rate of photosynthesis can be affected by four limiting factors. The amount of light the plant has access to (and the wavelength). The chlorophyll uses light energy to perform photosynthesis and it can only do this as fast as the light is
Rate of photosynthesis
Rate of Photosynthesis Planning Introduction Photosynthesis is the process whereby plants and certain photoautotroph make food using carbon dioxide and water. When both (carbon dioxide and water) are combined, they make the food; glucose as well as oxygen, given off as a by-product. The above description of photosynthesis can be analysed in the equation below: BALANCED CHEMICAL EQUATION 6CO2 + 6H2O=C6H12O6 + 6O2 WORD EQUATION Carbon Dioxide + Water=Glucose + Oxygen Factors that affect photosynthesis: LIGHT: insufficient light slows down the rate of photosynthesis CARBON DIOXIDE: similarly, inadequate quantity of carbon dioxide slows down the rate of photosynthesis. TEMPERATURE: temperature should not be too cold nor too hot. Aim My aim is to investigate whether the factor 'light', has an affect on the rate of photosynthesis. This will be observed by counting the number of oxygen bubbles given off. Apparatus * Metre rule * 5cm Canadian pondweed clipped on a paperclip * Beaker * Lamp, with 60 watts bulb * Water Hypothesis It is predicted that, the more light intensity the higher the rate of photosynthesis, providing that the temperature is not too cold or too hot. I would try and expect the below graph: Method The most vital thing, which is needed for photosynthesis is a plant. The plant which will be used in this investigation is a Canadian pondweed. The
Rate of Photosynthesis
Rate of Photosynthesis Aim: To investigate a factor that affects the rate of photosynthesis. Outline: A piece of pond weed will be cut and placed into a beaker containing water and sodium hydrogen carbonate. A lamp will be shined on to the pond weed and the amount of bubbles released from the plant will be counted. The lamp will be adjusted to different distances from the plant to try and obtain different results. Photosynthesis Equation: 6CO2 + 6H2O light energy & chlorophyll C6H12O6 + 6O2 Variables: Experimental Variable- Light intensity is to be the variable explored in this investigation. Light intensity can be varied by increasing or decreasing the distance from the light source to the plant. Fixed Variables- Light Wavelength (color)- Light energy is absorbed by pigments in the leaf such as chlorophyll. Chlorophyll easily absorbs blue light, in the 400-450 nm range, and also easily absorbs red light in the 650-700 nm range. Chlorophyll does not absorb green light or yellow light effectively but tends to reflect them, decreasing the amount of light absorbed and decreasing the rate of photosynthesis. Why the rate of photosynthesis increases or decreased from the amount of light energy absorbed is what is being investigated in this experiment. The light color can be fixed by using the same lamp throughout the experiment. Carbon Dioxide- CO2 concentration can
